def greet_user(username):
    print(f"Hello,{username.title()}!")
greet_user('jesse')

#练习8-1
def display_message():
    print("学的什么呢？")
display_message()

#8-2
def favorite_book(title):
    print(f"One of the favorite books is {title}")
favorite_book('python数据结构')